The invention relates to a valve for a container for dispensing pressurized fluid according to the preamble of claim 1.
A valve of this type is known from EP 0 350 779 B1. This valve comprises a valve body which may be mounted on a container lid. The container lid is fastened on a container, usually on a can. The valve body accommodates a closure member which is arranged in a passage of the valve body. The closure member is provided with a sealing which consists of at least one sealing lip. When the closure member is in a closing position, the sealing abuts on a valve seat provided in the passage of the valve body and closes the passage. By means of holding means which abut on the valve body, the closure member is displaceably arranged within the valve body and is held in a closing position when it is in its non-actuated position.
Valves of this type are used, for example, in aerosol cans containing a medium that cures after its application. The fluids conserved and discharged usually include polyurethane foams and adhesives. These polyurethane foams are humidity-sensitive and cure even under normal atmospheric conditions, due to the moisture present in the air. On discharging such a fluid, in particular in cases in which a can is not completely emptied in one work cycle, an opening and closing movement of the valve body is performed. Due to said curing property of the fluid, a curing of the fluid will occur, for example, in a region between a sealing lip and a punch portion of the valve body, producing a hard and at least partially annular remainder of cured fluid. In the course of a subsequent opening and closing of the valve for a further discharging of fluid, the at least partially annular remainder of cured fluid which has been formed may become detached, either entirely or in part, and get between the valve seat and the sealing, or near the at least one sealing lip, as the valve is subsequently closed. This may cause damage to the valve seat and/or the sealing lip, such that a complete closing may no longer be ensured. Thus, either pressurised fluid may continue to escape or air may enter into the interior of the container due to the non tightly sealing valve and cause a curing of the fluid inside the container.